Youtube is SUCH a treasure trove of James Burke stuff! Here is a clip which includes James Burke's commentary during the radio blackout moment, when Apollo 13 was re-entering the atmosphere, but due to the technical problems during the flight, nobody was sure if the heat shields would hold up. If they hadn't, the astronauts would have been fried alive. The re-entry section of the video clip starts around minute 1:30.
You can watch the same moment in the movie Apollo 13 here. I cry at the end of this movie every damn time.